Patent GB-414451-A (GB)
Title: Improvements in and relating to line spacing mechanism for typewriters and like machines
IPC: B41J19/84
Filed: 1933-03-10
Abstract: 414,451. Typewriters. MACDONALD, S., Noiwood East, Victoria Road, Gourock, Renfrewshire. March 10, 1933, No. 7297. [Class 100 (iv).] Line-spacing mechanism.-For effecting variable spacing without preliminary adjustment of the mechanism, the carriage is provided at one end with two or more line-spacing levers for effecting different spacings, or is provided with a single line-spacing lever which can be so manipulated as to effect different spacings. In the mechanism shown in Fig. 2, two line-spacing levers 11, 12, for normal and wide spacing respectively, are pivoted on a housing 6 on the carriage, and the lever 11 is connected by a link 14 to a rocking arm 7 provided with a paw 9 co-operating with a ratchet-wheel 19 geared to the platen-shaft. When the lever 11 is operated, the pawl is arrested by a stop-arm 16 on the lever 12. When the lever 12 is operated, the stop-arm is displaced, the lever 11 is operated by a lug 15, and the pawl is arrested by a stationary stop 17. To provide for another spacing, an additional line-spacing lever having a stop-arm may be embodied in the mechanism. The spacing can be adjusted by an adjustable mask or back-stop for the pawl. To prevent lost-motion, the gearing may include a pinion consisting of two relatively movable toothed discs constrained by resilient means. In the mechanism shown in Fig. 9, a lever 21 pivoted on the carriage and connected to the linespacing pawl supports a sleeve 22 having a hook 24 for engaging a lug 26 on a stop-arm 25. When the lever 21 is operated directly, the pawl is arrested by the stop-arm, and normal line-spacing is effected. When the lever is operated by means of a finger-piece on the sleeve 22, the hook displaces the stop-arm, the pawl is arrested by a stationary stop 27, and wide line-spacing is effected. In another mechanism, a universally mounted line-spacing lever, if depressed before being operated, displaces a stop-arm and effects wide line-spacing. In another mechanism, two line-spacing levers are mounted at one end of the carriage and are connected to pawls co-operating with adjacent ratchet-wheels. In the mechanism shown in Fig. 18, two or more line-spacing levers 50-52 abut on a lug 56 on a rocking plate 54 connected to the line-spacing pawl. The line-spacing levers have graded extensions 60 for cooperating with a stop 57 to determine the spacing. The stop may be arranged to engage directly the line-spacing levers, the extensions being omitted. For adjusting the spacing, a stepped, pivoted stop may be employed. In the mechanism shown in Fig. 21, a horizontal ratchet-wheel 70, geared to the platen, cooperates with a pawl 69 on a rocking arm 61 on which the line-spacing lever 63 is pivoted horizontally. A loosely mounted block on the lever is formed with steps 64, 64<a> for engaging a stop 65. For normal spacing the lever is moved horizontally and is arrested by engagement of the step 64<a> with the stop. For narrow or wide spacing, the lever is depressed or raised, before being moved horizontally, and is arrested by engagement of the step 64 or the pawl with the stop.